Obesity is a common and preventable disease of clinical and public health importance. It is often a major risk factor for the development of several non-communicable diseases, significant disability and premature death.This study was done to evaluate the serum activity of ALT, ALP and GGT among obese subject in Khartoum state. Fourtyobese Sudanese individuals with BMI more than 30 and 40 individuals with normal BMI as control were involved. serum activity of ALT, ALP and GGT were measured in order to assess the redundancy of obesity on serum ALT, ALP and GGT activity using DIRUI DR-7000D auto-analyzer.The results of this study showed significant increase in the mean of ALT (29.93±13.971 U/L) in obese compared with the control group (21.28±6.980U/L) P=0.001, and showed significant increase in the mean of ALP (246.60± 42.15,176.25±45.87 U/L) in case and control group respectively (P=0.000). the results wereinsignificant in the comparison between the enzymes activity of ALT, ALP and the gender (p=0.557, 0.301) respectively, and were significant with GGT and gender (p=0.000).Also, the result of this study showed significant increase in the mean of GGT (33.70±13.92, 24.60±8.22 U/L)in case and control group respectively ( P=0.001). The results showed positive correlation between enzymes activity of ALT,ALP,GGT and BMI (r=0.343,0.503,0.237, P=.002,0.000,0.034) respectively.Also the results showed no correlation between ALT and ALP with the duration of obesity (p=0.134,0.081) respectively, and positive correlation with GGT (r=0.461, p=0.003)In conclusion:obese individuals had higher serum activity of ALT, ALP and GGT and this might increase the risk of liver diseases compared with normal individuals